Investigations are proposed to more clearly delineate the mechanisms by which cadmium modifies drug responses and mechansims of cadmium toxicity. Among the studies proposed are: (1) influence of cadmium on endocrine factors (testicular and adrenal), (2) identification of the spectrum of therapeutic agents affected by cadmium, (3) role of cadmium-induced metallothionein in modifying drug response and toxicity to cadmium, (4) behavioral effects of cadmium, (5) role of cadmium-induced skeletal deformities including the influence of cadmium on the gastro-intestinal absorption of calcium.